Wettable silicone hydrogel compositions and methods for their manufacture

Abstract

Improved silicone-containing hydrogels are disclosed with enhanced wettability comprising a silicone-containing monomer, at least one acrylic-containing hydrophilic monomer, and at least one vinyl-containing hydrophilic monomer.

We claim: 
     
       1. In a silicone-containing hydrogel composition formed by curing a monomer mixture comprising at least one silicone-containing monomer and a hydrophilic monomer, the improvement of which comprises combining the silicone-containing monomer with N-vinylpyrrolidone and N,N-dimethylacrylamide in the monomer mixture. 
     
     
       2. The hydrogel of claim 1 wherein the weight ratio of N-vinylpyrrolidone to N,N-dimethylacrylamide present in the monomer mixture is from about 1:40 to about 40:1 
     
     
       3. The hydrogel of claim 1 wherein the combined weight percent of N-vinyl pyrrolidone and N,N-dimethyl acrylamide in the monomer mixture is from about 5 to about 80 weight percent. 
     
     
       4. The hydrogel of claim 1 wherein the combined weight percent of N-vinyl pyrrolidone and N,N-dimethyl acrylamide in the monomer mixture is from about 20 to about 60 weight percent of the polymeric hydrogel mixture. 
     
     
       5. The hydrogel of claim 1 wherein the Young's modulus of elasticity of the silicone containing hydrogel is from about 5 g/mm 2  to about 400 g/mm 2 . 
     
     
       6. The hydrogel of claim 1 wherein the silicone-containing monomer is a polyorganosiloxane monomer. 
     
     
       7. The hydrogel of claim 1 wherein the silicone-containing monomer is an α, ω bis(methacryloxyalkyl) dimethacrylate polysiloxane. 
     
     
       8. The hydrogel of claim 1 wherein the silicone-containing monomer is a bulky polysiloxanylalkyl (meth)acrylate monomer. 
     
     
       9. The hydrogel of claim 8 wherein the bulky polysiloxanylalkyl (meth)acrylate monomer is selected from the group consisting of methyloxypropyl tris(trimethylsiloxy) silane, pentamethyldisiloxanylmethylmethacrylate, tris(trimethylsiloxy)methacryloxy propylsilane, phenyltetramethyldisiloxanylethyl acrylate, and methyldi(trimethylsiloxy)methacryloxymethyl silane. 
     
     
       10. The hydrogel of claim 1 wherein the monomer mixture comprises N-vinylpyrrolidone, N,N-dimethylacrylamide and an α, ω bis(methacryloxyalkyl)dimethacrylate polysiloxane. 
     
     
       11. In a contact lens formed from the polymerization product of a monomer mixture comprising at least one silicone-containing monomer and a hydrophilic monomer, the improvement of which comprises combining N-vinylpyrrolidone and N,N-dimethylacrylamide with the silicone-containing monomer in the monomer mixture. 
     
     
       12. The contact lens of claim 11 wherein the weight ratio of N-vinylpyrrolidone to N,N-dimethylacrylamide present is from about 1:40 to about 40:1. 
     
     
       13. The contact lens of claim 11 wherein the combined weight percent of N-vinyl pyrrolidone and N,N-dimethyl acrylamide in the monomer mixture is from about 5 to about 80 weight percent of the polymeric hydrogel mixture. 
     
     
       14. The contact lens of claim 11 wherein the combined weight percent of N-vinyl pyrrolidone and N,N-dimethyl acrylamide in the monomer mixture is from about 20 to about 60 weight percent of the polymeric hydrogel mixture. 
     
     
       15. The contact lens of claim 11 wherein the Young's modulus of elasticity is from about 5 g/mm 2  to about 400 g/mm 2 . 
     
     
       16. The contact lens of claim 11 comprising N-vinylpyrrolidone, N,N-dimethylacrylamide and an α, ω bis(methacryloxyalkyl)dimethacrylate polysiloxane.